Pilot turning attachment for lathes



flona/z/ $11501 ercy wee/en Dec. 12, 1950 D. DU BOIS ET AL PILOT TURNINGATTACHMENT FOR LATHES Filed Nov. 5, 1945 Patented Dec. 12, 1950 UNITEDSTATES PATENT OFFICE 1 1L052 TURNING ATTACHMENT FOR LATH'ES Donald DuBois, Ashokan, and Percy Wheeler, Poughkeepsie, Y.

Application November 3, 1945, Serial No. 626,532

2 Claims. 1

This invention relates to lathe attachments and accessories and has morespecific reference to a comparatively small and simple device which wehave chosen to identify as a pilot turning attachment, the same havingbeen expressly designed as an improvement over the now customarily usedor conventional two-roller type t-urners. Attachments of theaforementioned types are employed and used on lathes for stabilizingsmall sized stock rangn from one-sixteenth to threeeighths of an inch indiameter and are employed to overcome the tendency of stock to flex andspring away from the cutting end of the tool bit. Unless the .free endof the stock, adjacent the cutting tip of the tool is in some mannersupported and held against fluttering and whipping, it is d fficult. ifnot almost impossible, to cause the tool to take a proper cut on thestock or work. In accordance with the principles of the instantinvention, we contemplate the provision of a simple and expedientattachment which is applicable to the regularly used adjustable tool,said attachment being provided with a work piloting and retainingbearing, whereby the work is saddled, as it were, on the tool in orderto maintain the proper relationship of parts for effective turning andcutting results.

Briefly, and in carrying out our invention, we contemplate the provisionof a simple and feasible attachment characterized by two principalparts, a body which clamps adjustably on and is supported by the regulartool bit and a plate carried by said body and adjustable on the body,said plate being aper-tured and having roller bearing means fitted insaid aperture, said roller bearing means serving to embrace andstabilize the free flexible end of stock or work, whereby it becomespossible to bring the cutting end of the tool bit and work into steadiedrelationshp during the period of the turning and cutting steps.

Other objects, features and advantages will become more readily apparentfrom the following description and the accompanying illustrativedrawings.

In the drawings, wherein like numerals are employed to designate likeparts throughout the views:

Figure 1 is a top plan view il ustrating fragmentary portions of aconventional lathe, showing the stock or work in the collet, the tool onthe I post, the attachment on the tool; all parts set for usefuloperation.

Figure 2 is a View in edge elevation of the attachment per se showing itfastened on the tool bit.

Figure 3 is a view at right angles to Figure 12 observing same in adirection from right to left.

l igure 4 is a section on the line 4-4 of Figure 3, looking in thedirecton of the arrows.

Figure 5 is a view of Figure 2, observing same in a direction from leftto right and employed to bring out the adjustable mounting of the plateon the body.

Referring now to the drawing by distingushing reference numerals andattention being had to Figure 1, it will be seen that the referencecharacter A designates, in a general way, the headstock of aconventional lathe having associated therewith the usual collet B withthe stock or work C removably and adjustably clamped in said collet andextend ng centrally therefrom. The frame structure D includes supportingguides E for the shiitable carriage structure F. The letter G designatesthe so-called compound, while H denotes a single style tool post and T,the regular or standard tool or tool bit. The tool is shown adjustablysupported in the tool post with its cutting end J located in cuttingrelationsh p to the tip K of the stock or work C. The improved pilotturning attachment, as a unit, is denoted by the numeral 8. In Figure 1this is shown occupying complete operative positions, the same connectedat one end to the tool T and at the opposite end to the stock C. Wemight add that the cross slide, which is also shown, is denoted by theletter L.

It is obvious that the invention is difierentiated,

as an entity, by the numeral '8. As before indicated, it comprises ablock-like body Q, this of rectangular form as shown in Figures 2 and 3,the same having a groove it! in one side forming a key-way for the shankH of the cutting tool. The cutter end J projects beyond the groove inthe block and the parts are assembled and held together by set-screws[-2 in the block or body securing the tool in the key-way or groove. Theso-called plate, which is of the shape shown in Figure 3, is denoted bythe numeral 113. This fits in the grooved or shouldered portion 14 ofthe body or block s. As shown in F gure '5, elongated slots t5 areprovided in the plate on one side and the plate is countersunk aroundthe slots as indicated at Ilia. These slots l5 serve to accommodatebolts it thread-ed into sockets provided in the block or body 9. Theslot connections serve to adjustably mount the plate on the body andmake allowances for subsequent adjustments necessary to bring aboutcentering of the plate respect to the body. The plate, as shown inFigure 4, is provided with a piloting aperture or circular hole I! forthe stock and also the plate is Figs. 1 and 3, to restrict orconcentrate the field adjacent the tube neck and hence the beamcountersunk as at IE to provide a circular recess to accommodate theroller bearing unit 9. The unit includes an inner race 29 of a properdiameter to snugly receive and surround the stock, as shown. Thus, thestock is supported in the inner race 29 or the ball bearing, rather thanin the aperture H.

In operation an ordinary three-eighths inch tool bit is placed in asingle or four-way tool post (not shown) in the usual manner and islocated on center. After taking several cuts in getting a cross-slidereading on the diameter desired, an attachment 8, that is, a pilotturning attachment, of the necessary size is selected. The completeattachment is then placed over the tool bit as shown in Figure 1 andpositioned by sliding forward or back on the tool bit with the clampingscrews !2. When the pilot is over the stock properly with the stockextending through the bearing or rather the inner race 29, the screws 12are tightened. Thus, the parts are set up for coaction and operation asshown in Figure 1 of the drawings.

It will be appreciated, having studied the drawings in conjunction withthe description, that the attachment as a unitary assemblage, is easyand quick to apply and adjust. The desired size on the'cut is arrived atby feeding the cross-slide rather than tapping the tool bit as is in thecase of the conventional two-roller type turner. The attachment permitsheavier cuts with greater certainty of size and substantially eliminatesdrift of small diameter stock, permitting a piece of almost any lengthto be satisfactorily held and turned. The attachment has its greatestuse in the large quantity of production of small pins, studs, etc. i

So far as we have been able to ascertain, as a result of studiedconsideration of the specific field of invention under advisement, noone prior to us has devised and used a pilot turning attachment forlathes which is characterized by a simple economical, rectangular metalblock or body which has a centralized groove functioning as a channeland opening through opposite ends'of the body to seat a correspondinglyshaped tool bt wherein the bit, when inserted in the groove or channelis allowed to extend through and beyond both ends of the channel withone end to coact with the work piece and the other end to be supported,in the usual way, in a conventional-type tool post, the connectionbetween the body and shank of the tool bit being effected by simple setscrews. We emphasize this because .we utilize the tool bit as the solesupport for the block-like body. Secondly, the connection between theshank of the bit and the body is not only adjustable so that the bodymay be slid lengthwise along the shank of the tool bit, but theconnection between the body and the bit is separable. This allows thebody to be detached, making it possible to remove our entire unit fromthe tool bit expediently while further cuts of a different nature aremade by the same tool bit. What is more, novelty is predicated upon thenotched end portion of the body which provides a shoulder and ledge forour novel plate. This is such that the two parts couple together nicelyas brought out especially in Figures 2 and 4 of our drawings. Also, weemphasize the bolt and slot connection between the parts 8 and 9 thuspositioning the plate 8 0n the side of the body opposite to the point ofanchorage of the tool bit. Thus, the plate with its bearing is offsetand lies in a plane spaced in parallelism from the projecting end J ofthe bit as brought out to advantage in Figure 2 of our drawings. What ismore, the bolt and slot connecting means allows the bearing means,particularly the inner race 29, to be centered in relation to the workand tool bit. Consequently, the body 9 is adjustable and detachable inrelation to the tool bit and is supported wholly by the tool bit, Theplate carrying the bearing is ofiset as shown in Figure 2 and isdetachable and also adjustable in relation to the tool bit and body 9.

Minor changes in shape, size, materials and rearrangement of parts maybe resorted to in actual practice so long as no departure is made fromthe invention as claimed.

We claim:

1. A pilot turning attachment for lathes comprising a rectangularblock-like body having flat forward, rearward and marginal surfaces andprovided in its rearward surface with a groove opening through oppositemarginal edges and. provided with set screws projecting into saidgroove, said groove being adapted to receive the shank portion of a toolbit, a tool bit having its shank portion nested in said groove and heldin place by said set screws, said tool bit constituting the sole supportfor said body, said body being detachable and adjustable in relation tothe tool bit and one projecting end of the tool r bit being adapted tobe mounted in a conven tional tool post, a plate detachably andadjustably mounted on the forward surface of said body and projecting.beyond the adjacent marginal edge, said plate having a centeredanti-friction bearing adapted to completely embrace and steady the freeend of the stock to be turned and cut by said tool bit, said bearingbeing eccentric to the longitudinal axis of said tool bit and lying in aplane in spaced parallelism in relation to the adjacent end of said toolbit.

2. The structure specified in claim 1 wherein the stated forward surfaceof said body has an open ended notch providing a shoulder and ledge, thecoacting portion of said plate abutting said shoulder and slidablycontacting said ledge and having bolt slots, said slots being at rightangles to the longitudinal axis of the tool bit, and bolts fittedthrough said slots and anchored in said ledge to allow the plate and itsbearing means to be shifted in respect to the body for centering thebearing means in relation to the tool bit.

DONALD DU BOIS.

PERCY WHEELER,

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATL NTS Number Name Date 238,509 Hoffman Oct. 19, 18801,161,056 Liebstein Nov. 23, 1915 2,373,301 Erickson Apr. 10, 19452,420,945 Gaylord May 20, 1947 FOREIUN PATENTS Number Country Date133,154 Great Britain Oct. 3, 1919

